IMPLANTATION OF A REINFORCED POLYTETRAFLUOROETHYLENE VASCULAR GRAFT FOR TREATMENT OF OBSTRUCTIONS OF THE TEAT AND MAMMARY-GLAND CISTERNAE IN CATTLE

Objective-To evaluate use of an artificial vascular graft as treatment for obstructions of the test and mammary gland cisternae in lactating cattle. Design-Prospective clinical study. Animals-14 lactating dairy cows. Procedure-After physical examination that included palpation, u ltrasonography, evaluation of milk flow, and California mastitis test, each cow underwent surgical excision of obstructive tissue and implan tation of a reinforced polytetrafluoroethylene vascular graft. Milk dr ained passively for 10 to 14 days after surgery. Follow-up evaluation was performed by telephone questionnaire of owners 1, 6, and 12 months after surgery regarding somatic cell count, time needed to milk affec ted quarter, compared with that of the contralateral quarter, and freq uency of mastitis. After the subsequent nonlactation period and calvin g, milk flow was tested, using a quarter milking machine, and ultrason agraphic examination of the affected leat was performed. Results-Milk could be obtained from affected quarters from all cows 14 days after s urgery, from 13 (93%) cows 1 month after surgery, from 10 (71%) cows 6 months after surgery, and from 3 (21 %) cows 12 months after surgery, but milk flow in these 3 cows was considerably reduced. This techniqu e failed because of collapse of the implant (4 cows), chronic mastitis (1), migration of the implant (4), and ingrowth of obstructive tissue between the distal aspect of the implant and the ridges of mucous mem brane that radiate from the internal orifice of the streak canal (4), or a combination of these. Clinical Implications-Implantation of this vascular graft is a useful technique to restore teat patency for 6 mon ths. A longer period of passive drainage of milk appears necessary for sufficient ingrowth of the graft. Lesions that extend to the distal m ost aspect of the teat cistern have a poor prognosis, because this are a cannot be sufficiently overlapped by the graft.